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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 22 |
| 5 | 51 |
| 6 | 121 |
| 7 | 292 |
| 8 | 704 |
| 9 | 1691 |
| 10 | 4059 |
| 11 | 9749 |
| 12 | 23422 |
| 13 | 56268 |
| 14 | 135166 |
| 15 | 324692 |
| 16 | 779977 |
| 17 | 1873673 |
| 18 | 4500958 |
| 19 | 10812237 |
| 20 | 25973244 |
| 21 | 62393157 |
| 22 | 149881402 |
| 23 | 360046432 |
| 24 | 864906711 |
| 25 | 2077686532 |
| 26 | 4991036946 |
| 27 | 11989513056 |
| 28 | 28801314179 |
| 29 | 69186771332 |
[1,3,9,22,51,121,292,704,1691,4059,9749,23422, 56268,135166,324692,779977,1873673,4500958, 10812237,25973244,62393157,149881402,360046432, 864906711,2077686532,4991036946,11989513056, 28801314179,69186771332] |